For either the M Type 240 or NEX, it won't matter whether you buy 1/2/3-cam or ROM lenses. However, profiles for certain lenses can be set manually on the M240:

Now, and for the first time ever, the new Leica R-Adapter M enables almost all Leica R-Lenses ever built to be mounted on the new Leica M. Users can access a list of 20 dedicated profiles - including calibrated imaging workflows and EXIF lens recognition - for a range of R-Lenses covering wide-angle, standard, telephoto, zoom and macro lenses. This comprehensive portfolio of lenses opens up new potential for Leica M photographers, for example, video recording with Leica R zoom lenses.

Funny you mention this Joe - I was thinking of adding this as my next R lens for M240. I have seen so many nice images - I want to try it out. The only thing I am unsure of is the FL. I have found that around 100-150mm FL is typically the best for myself when doing any macro work. Having said that, I would probably only use it for macro around 10% of the time....

Gary, I think the M240 with live view opens up a lot of avenues when it comes to lenses including all of the older OM, FD, Nikon, C/Y, etc etc. Am really liking this aspect of the M240, except that its putting a dent in my bank account very quickly.

As for macro, depending on what you shoot, depth of field on the longer FL might be an issue to get acceptable focus. Sometimes you may have to stop down to f/16 or f/22. So it depends on what you are shooting?

I asked my dealer today and the R adapters are still not available yet. Will probably get a cheaper fotodiox to try out first.

Gary Clennan wrote:
Funny you mention this Joe - I was thinking of adding this as my next R lens for M240. I have seen so many nice images - I want to try it out. The only thing I am unsure of is the FL. I have found that around 100-150mm FL is typically the best for myself when doing any macro work. Having said that, I would probably only use it for macro around 10% of the time....

The Elmarit-R-Macro 60mm is great for both close-range and distance shooting.

joe88 wrote:
I asked my dealer today and the R adapters are still not available yet. Will probably get a cheaper fotodiox to try out first.

For a brief moment I thought that the ROM lenses would allow communication with the M 240 body -- until I remembered that there are no electrical contacts to communicate with. I can't see the Leica adapter offering any advantage over the Fotodiox. And the Novoflex R to M adapter is only $40 cheaper than Leica's own adapter.

I think Leica's own adapter will somehow allow manual selection of R lenses for EXIF data. Right now, when I manually select lenses in the M240, only M mount lenses are displayed, none of the R lenses show up. I'll need to read up some more on this as the EXIF data would be useful for cataloging.

According to my reliable source, the M240 was code named MR10 internally. It was considered to be the solution for R user after the R10 project was cancelled. However, Leica did not much advertise M240 in this way. I'd still suggest getting ROM lenses instead of 3 CAM ones. It is possible the authentic R adapter might take advantage of ROM contact in the future. (It 'may' support auto switching focus live view when you turned your R lenses)

I guess that the original Leica R-M adapter has a six bit code on the back, so the M240 'knows' that the adapter is mounted and allows then to manually select profiles for different R lenses. How useful those profiles are for real I don't know; probably there're corrections for vigneting and distortion ?.
Anyway, it seems very unlikely that a future adapter would be able to read the info of ROM lenses. That requires a modified M mount with electrical contacts around the mount throat to pass the information to the body. There's no way that the current M240 will be able to recognize automatically a R lens, with or without ROM contacts.

Just looked at prices online and those ROM lenses are even more expensive than some of the new M mount ASPH lenses

I don't know if there is correction for vignetting and distortion, but EXIF focal length info alone would be helpful to help identify focal length later on

I think many M users would use the longer R or macro lenses since there are so many excellent M lenses to try. Its the longer end, past 135mm which makes things interesting, at least for me. The M240 is not a R solution and especially on longer tele lenses, the EVF lags too much, can't zoom to focus magnify off center and there is serious jello (line skipping) especially on longer focal lengths. When I put on my 135mm M lenses and tried to move around slowly in 5 or 10x magnified mode, the entire EVF image looks like an earthquake with the lag. But otherwise, the M240 does have a really nice fun factor to it. I can now experiment and shoot all types of legacy DSLR lenses with cheap adapters.

The ROM lenses tend to be more expensive than the 3 cam versions of the lenses. Some of the last lenses to be introduced were only available as ROM versions. Unless you plan to use a lens on a Leica R8 or R9, I suggest purchasing the 2 Cam or the 3 Cam versions of the lenses (that is unless there were changes in the lenses (and very few lenses had any changes) during the changeover from 3 Cam to ROM versions.

I very much doubt that any M camera will ever take advantage of the ROM contacts of the ROM lenses. Unless there is no option but a ROM lens in certain lenses I suggest the 3 CAM lenses unless you get a really good deal on the lens. I only have a small number of ROM lenses including my 35mm-70mm f4 Vario Elmar and my 80-200mm f4 Vario Elmar lens. The only lens that I had changed was my 280mm f2.8 Apo Telyt that was modified (and may have been the first changed in the US) in about 1998. I believe all my other lenses are 3 Cam lenses with the exception of my 100mm f4 Bellows Macro Elmar lens and my 560mm f6.8 Telyt lens which I believe are 2 Cam.

phuang3 wrote:
According to my reliable source, the M240 was code named MR10 internally. It was considered to be the solution for R user after the R10 project was cancelled. However, Leica did not much advertise M240 in this way. I'd still suggest getting ROM lenses instead of 3 CAM ones. It is possible the authentic R adapter might take advantage of ROM contact in the future. (It 'may' support auto switching focus live view when you turned your R lenses)

unless there are electrical contacts on the mount of the m240 (there are't) there is no way for the m240 to take advantage of any ROM features unless the leica made adapter comes with a cord to connect somewhere else on the body (it won't). as for auto switching to LV when you turn your R lens focus ring, this is impossible because there is no mechanism in the R lens itself to indicate when the focus ring is turned. on an unrelated note, i find the auto jump to magnified LV incredibly annoying on cameras that do have it.

Joe, I don't think ROM make the contact to give EXIF info but the Leica adapter with 6 bit code so that M240 will give you the option to manual select it.

However, I do notice ROM is noticeable more expensive than other version, part of reason obviously because it is newer, but also Leica usually change their coating without notice, the newer most likely have newer coating.

Why you want this 60 for your M, Macro? Leica M is very strong at 50 region

sebboh wrote:
on an unrelated note, i find the auto jump to magnified LV incredibly annoying on cameras that do have it.

I also thought the same the first time I used this feature. However, after using it in certain situations (longer tele lenses, portraits, etc) it works very well for me. I have never used it for shorter FLs as there is really no need.

Gary Clennan wrote:
I also thought the same the first time I used this feature. However, after using it in certain situations (longer tele lenses, portraits, etc) it works very well for me. I have never used it for shorter FLs as there is really no need.

yeah, I don't mind it as much for static subjects but most of my shooting these days is children running around where the auto zoom feature is the worst thing in the world.

zhangyue wrote:
I do notice ROM is noticeable more expensive than other version, part of reason obviously because it is newer.

ROM lenses are not always newer. Older lenses could be converted to ROM.

joe88 wrote:
Does it matter if I buy a 1-2-3 cam or ROM lens for my purposes? The newer ones probably have improved coatings and mechanics even with the same optical formula?

The 60mm Macro-Elmarit-R was never available as a 1-cam lens. If anything the older lenses have better mechanics; less substitution of plastic for metal.

Since you're not going to use it on a Leica-R body more important than cams IMHO is the filter size. The older models use a Series VIII filter held in place by the dedicated hood. The old models can also use a 60mm threaded filter. Newer models use 55mm filters. I use a 60mm circular polarizing filter on my 100mm macro so the older 60mm Macro allows me to use the same filter on both lenses without using a step-up ring.